Remove redundant entrypoint text normalization
Remove redundant entrypoint text normalization

Currently we do processing in `get_entrypoints` so incoming text is more compatible
with `pkg_resources`. It turns out that `pkg_resources` is already doing the same normalization,
so we can omit it.

This simplifies `get_entrypoints`, opening the way for us to pass it a plain string instead
of a file path.

pfmoore/pip,pypa/pip,pfmoore/pip,sbidoul/pip,pypa/pip,sbidoul/pip,pradyunsg/pip,pradyunsg/pip